[src/trunk]: src/sys/rump/librump/rumpvfs Don't create a huge number of unnec...

[pooka <pooka%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/14025efcbdfe
branches:  trunk
changeset: 785866:14025efcbdfe
user:      pooka <pooka%NetBSD.org@localhost>
date:      Wed Apr 03 20:23:01 2013 +0000

description:
Don't create a huge number of unnecessary device nodes automatically.
Creating them takes 70-or-so ms on a RPi, and can almost double the
bootstrap time of a rump kernel on that hardware.

diffstat:

 sys/rump/librump/rumpvfs/rump_vfs.c |  21 +++++++++++++++++----
 1 files changed, 17 insertions(+), 4 deletions(-)

diffs (50 lines):

diff -r c594a3e24742 -r 14025efcbdfe sys/rump/librump/rumpvfs/rump_vfs.c
--- a/sys/rump/librump/rumpvfs/rump_vfs.c       Wed Apr 03 20:21:38 2013 +0000
+++ b/sys/rump/librump/rumpvfs/rump_vfs.c       Wed Apr 03 20:23:01 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rump_vfs.c,v 1.71 2013/01/14 16:45:47 pooka Exp $      */
+/*     $NetBSD: rump_vfs.c,v 1.72 2013/04/03 20:23:01 pooka Exp $      */
 
 /*
  * Copyright (c) 2008 Antti Kantee.  All Rights Reserved.
@@ -29,7 +29,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rump_vfs.c,v 1.71 2013/01/14 16:45:47 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rump_vfs.c,v 1.72 2013/04/03 20:23:01 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/buf.h>
@@ -91,8 +91,6 @@
 
 RUMP_COMPONENT(RUMP__FACTION_VFS)
 {
-       extern struct devsw_conv devsw_conv0[];
-       extern int max_devsw_convs;
        extern struct vfsops rumpfs_vfsops;
        char buf[64];
        int error;
@@ -180,7 +178,22 @@
 
        module_init_class(MODULE_CLASS_VFS);
 
+       /*
+        * Don't build device names for a large set of devices by
+        * default.  While the pseudo-devfs is a fun experiment,
+        * creating many many device nodes may increase rump kernel
+        * bootstrap time by ~40%.  Device nodes should be created
+        * per-demand in the component constructors.
+        */
+#if 0
+       {
+       extern struct devsw_conv devsw_conv0[];
+       extern int max_devsw_convs;
        rump_vfs_builddevs(devsw_conv0, max_devsw_convs);
+       }
+#else
+       rump_vfs_builddevs(NULL, 0);
+#endif
 
        rump_component_init(RUMP_COMPONENT_VFS);
 }